the yeti will have better sound quality than the snowball.
the snowball is well known to have volume issues where it sounds too quiet without turning gain up. as far as i know the yeti doesnt have any such issues.
if you are considering the yeti then it would be worth considering either the atr2500 or at2020usb+ as well. much smaller microphones and excellent vocal quality. they are only 1 mode though (cardioid, which is ideal for vocal pickup)